Monkeys were preoperatively trained on an auditory version of recognition memory with a stimulus set of 1000 complex sounds, each lasting 1-2 sec, and then examined with variable recognition delays (between a sample and a test stimulus) of 5-50 sec. Postoperative results indicate that perirhinal/entorhinal (i.e. rhinal) lesions, which are known to produce severe impairment in both visual and tactile recognition memory, have no effect on the auditory version of this mnemonic ability. The finding points to an unexpected difference in the organization of sensory-limbic interaction underlying stimulus memory in the different exteroceptive modalities. Selective responses of neurons in the auditory lateral belt areas, which receive input from the primary auditory areas, seem to be due mainly to temporal and spectral integration across frequencies rather to differences in frequency, per se. To test this notion further, we used a standard set of monkey vocalizations and their components as stimuli. We have found some lateral-belt neurons that display temporal combination sensitivity (in which the response to the whole monkey call is greater than the sum of the responses to individual components), other lateral-belt neurons that show temporal suppression (in which the response to one component of the call is reduced when it is preceded or followed by another component of the call), and still other neurons that show both types of nonlinear interaction. The proportion of neurons showing these complex selectivities is greater in the lateral belt than in the primary auditory areas, supporting the existence of an auditory processing hierarchy within the superior temporal gyrus.